It's confession time. When I was just a lad of about 20, I was returning from Munich to JFK on DL. I had run terribly late for the flight and the gate agents were shutting the door as I ran down the jetway. As I walked through First, my bags began to slip and I just made to an empty Biz Class seat before I dropped everything. Two FAs rushed up, one took my bags from me and said she'd find a place for them, and the other gently pushed me into my seat, said to strap in because we were pushing back, and handed me a glass of champagne! I knew right away they thought that was my seat, but I just couldn't bring myself to stand up and tell the truth. That was my first flight in Biz ever and I was totally hooked! :-)
To this day I feel guilt over that flight, so I hope the DL gods will forgive me for my transgression! Now, as a tried-and-true road warrior, I hope I've repaid my sins over time...